"Unknown" logs in observability overview

Elastic Observability Logs
2

As described in the thread you linked, your best bet would be to use ECS loggers and to define the event.dataset field. If that's not an option, you can use an add_fields processor to manually add this field in your Filebeat configuration.

Example:

processors:
  - add_fields:
      target: ''
      fields:
        event:
          dataset: my-app.log